Analysis of the MLH1, MLH2, MLH6, PMS2 genes and their correlations with clinical data in rectal mucinous adenocarcinoma.

Background: Microsatellites are short repeated DNA sequences normally found in the human genome. Following specific mutations, microsatellites can vary in the number of repeats thus making the DNA unstable. Microsatellite instability (MSI) is responsible for approximately 20% of rectal cancers, while the remaining 80% are caused by chromosomal instability.